sex and behaviour

Answer 1

Female investment in the egg structure in
non-mammals or in the uterus and during
gestation in mammals.

Question 2

parental investment is costly but does what

Answer 2

Parental investment is costly but increases
the probability of production and survival of young

Question 3

what is the classification of r- selected and k selected organisms based on

Answer 3

Classification of r-selected (r-strategists) and K-selected (K-strategists) organisms based on level of parental investment in offspring and number of offspring produced

Question 4

what are characteristics of r selected species

Answer 4

Characteristics of r-selected species: smaller; have a shorter generation time; mature more rapidly; reproduce earlier in their lifetime, often only once; produce a larger number of smaller offspring, each of which receives only a smaller energy input; limited parental care; most offspring will not reach adulthood.

Question 5

what are characteristics of k selected species

Answer 5

Characteristics of K-selected species: larger
and live longer; mature more slowly; can
reproduce many times in their lifetime;
produce relatively few, larger offspring; high
level of parental care; many offspring have a
high probability of surviving to adulthood.

Question 6

when does r selection tend to occur as opposed to k selection

Answer 6

r-selection tends to occur in unstable
environments where the species has not
reached its reproductive capacity, whereas Kselection tends to occur in stable environments

Question 7

benefits and costs of external fertilisation

Answer 7

External fertilisation
 benefits: very large numbers of offspring
can be produced
 costs: many gametes predated or not
fertilised; no or limited parental care; few
offspring survive

Question 8

benefits and costs of internal fertilisation

Answer 8

Internal fertilisation
 benefits: increased chance of successful
fertilisation; fewer eggs needed; offspring
can be retained internally for protection
and/or development; higher offspring
survival rate
 costs: a mate must be located, which
requires energy expenditure; requires
direct transfer of gametes from one
partner to another

Question 9

what are mating systems based on

Answer 9

Mating systems are based on how many
mates an individual has during one breeding season. These range from polygamy (polygyny and polyandry) to monogamy

Question 10

define monogamy

Answer 10

Monogamy: the mating of a pair of animals to
the exclusion of all others.

Question 11

define polygamy

Answer 11

Polygamy: individuals of one sex have more
than one mate.

Question 12

define polgyny

Answer 12

Polygyny: one male mates exclusively with a
group of females (harem)

Question 13

define polyandry

Answer 13

Polyandry: one female mates with a number of males in the same breeding season. (reverse harem)

Question 14

Many animals have mate-selection courtship rituals. Successful courtship behaviour in birds and fish can be a result of what

Answer 14

Many animals have mate-selection courtship rituals. Successful courtship behaviour in birds and fish can be a result of species-specific sign stimuli and fixed action pattern responses

Question 15

ehat does sexual selection select for

Answer 15

Sexual selection selects for characteristics
that have little survival benefit for the
individual, but increase their chances of
mating

Question 16

sexual dimorphism

Answer 16

Many species exhibit sexual dimorphism as a product of sexual selection. Reversed sexual dimorphism occurs in some
species

Question 17

markings, structures and behaviour in males and females

Answer 17

Females are generally inconspicuous; males usually have more conspicuous markings, structures and behaviours.

Question 18

what does female choice involve

Answer 18

Female choice involves females assessing
honest signals of the fitness of males

Question 19

what do honest signals indidcate

Answer 19

Honest signals can indicate favourable
alleles that increase the chances of survival
of offspring (fitness) or a low parasite burden
suggesting a healthy individual.

Question 20

what happens in lekking species

Answer 20

In lekking species, males gather to display at
a lek, where female choice occurs

Question 21

birds exhibiting lekking behaviour

Answer 21

Some bird species exhibit lekking behaviour.
Dominant males occupy the centre of the lek,
with subordinates and juveniles at the fringes
as ‘satellite’ males. During the display,
female choice occurs.

Question 22

what does success in male-male rivalry increase

Answer 22

Success in male-male rivalry through conflict
(real or ritualised), increases access to
females for mating

Question 23

what will males fight for

Answer 23

Males will fight for dominance and access to
females, often using elaborate ‘weapons’
such as antlers, tusks, horns.